diff options
Diffstat (limited to 'arch/x86/include/asm/ibt.h')
| -rw-r--r-- | arch/x86/include/asm/ibt.h | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/arch/x86/include/asm/ibt.h b/arch/x86/include/asm/ibt.h index 689880eca9ba..28d845257303 100644 --- a/arch/x86/include/asm/ibt.h +++ b/arch/x86/include/asm/ibt.h @@ -21,7 +21,7 @@ #define HAS_KERNEL_IBT 1 -#ifndef __ASSEMBLY__ +#ifndef __ASSEMBLER__ #ifdef CONFIG_X86_64 #define ASM_ENDBR "endbr64\n\t" @@ -31,7 +31,17 @@ #define __noendbr __attribute__((nocf_check)) -static inline __attribute_const__ u32 gen_endbr(void) +/* + * Create a dummy function pointer reference to prevent objtool from marking + * the function as needing to be "sealed" (i.e. ENDBR converted to NOP by + * apply_seal_endbr()). + */ +#define IBT_NOSEAL(fname) \ + ".pushsection .discard.ibt_endbr_noseal\n\t" \ + _ASM_PTR fname "\n\t" \ + ".popsection\n\t" + +static __always_inline __attribute_const__ u32 gen_endbr(void) { u32 endbr; @@ -46,7 +56,7 @@ static inline __attribute_const__ u32 gen_endbr(void) return endbr; } -static inline __attribute_const__ u32 gen_endbr_poison(void) +static __always_inline __attribute_const__ u32 gen_endbr_poison(void) { /* * 4 byte NOP that isn't NOP4 (in fact it is OSP NOP3), such that it @@ -55,19 +65,24 @@ static inline __attribute_const__ u32 gen_endbr_poison(void) return 0x001f0f66; /* osp nopl (%rax) */ } -static inline bool is_endbr(u32 val) +static inline bool __is_endbr(u32 val) { if (val == gen_endbr_poison()) return true; + /* See cfi_fineibt_bhi_preamble() */ + if (IS_ENABLED(CONFIG_FINEIBT_BHI) && val == 0x001f0ff5) + return true; + val &= ~0x01000000U; /* ENDBR32 -> ENDBR64 */ return val == gen_endbr(); } -extern __noendbr u64 ibt_save(void); +extern __noendbr bool is_endbr(u32 *val); +extern __noendbr u64 ibt_save(bool disable); extern __noendbr void ibt_restore(u64 save); -#else /* __ASSEMBLY__ */ +#else /* __ASSEMBLER__ */ #ifdef CONFIG_X86_64 #define ENDBR endbr64 @@ -75,28 +90,29 @@ extern __noendbr void ibt_restore(u64 save); #define ENDBR endbr32 #endif -#endif /* __ASSEMBLY__ */ +#endif /* __ASSEMBLER__ */ #else /* !IBT */ #define HAS_KERNEL_IBT 0 -#ifndef __ASSEMBLY__ +#ifndef __ASSEMBLER__ #define ASM_ENDBR +#define IBT_NOSEAL(name) #define __noendbr -static inline bool is_endbr(u32 val) { return false; } +static inline bool is_endbr(u32 *val) { return false; } -static inline u64 ibt_save(void) { return 0; } +static inline u64 ibt_save(bool disable) { return 0; } static inline void ibt_restore(u64 save) { } -#else /* __ASSEMBLY__ */ +#else /* __ASSEMBLER__ */ #define ENDBR -#endif /* __ASSEMBLY__ */ +#endif /* __ASSEMBLER__ */ #endif /* CONFIG_X86_KERNEL_IBT */ |